Although there recently has been an increase in research investigating ADHD among adults (Barkley, Murphy, & Fischer, 2008), relatively less research has specifically addressed the manner in which ADHD impacts young adults attending college (DuPaul & Weyandt, 2009). The need for conducting such research has become more evident recently, as increasing numbers of students with ADHD have been enrolling in college (Pryor et al., 2010; Wolf, 2001). To address this situation, the goals of this proposed study are: (a) to investigate the developmental trajectory of functional impairments associated with ADHD in the college student population, and (b) to identify variables that may predict differential outcomes in this group. It is expected that college students with ADHD will exhibit significant deficits in educational, cognitive, social, psychological, and vocational functioning relative to non-ADHD peers. It is also expected that ADHD and non- ADHD control groups will show greater divergence in all functioning areas over time as the challenges of college performance increase. This study will be the first to systematically assess the educational, cognitive, social, psychological, and vocational functioning of college students with ADHD, relative to a sample of peers without ADHD, over time. Two waves of first year students will be recruited from ten university sites and followed throughout a four year period. Participants will be assessed twice each academic year across multiple domains of functioning via self-report, direct testing, and experience sampling methodology. All participants will undergo a rigorous initial assessment to be certain they meet stringent criteria for inclusion in the ADHD and non-ADHD control conditions. Separate latent growth curve analyses will be conducted to examine group differences over time within each area of functioning. The proposed study will be the first of its kind to shed much needed light on how ADHD and its associated impairments unfold across the college years. Obtained findings will provide direction for identifying evidence-based assessment methods and procedures that will be critical for addressing the mental health and educational needs of college students with ADHD. Results from this longitudinal investigation will also serve to guide the development of intervention efforts aimed at improving the long-term success of college students with ADHD. PUBLIC HEALTH RELEVANCE: At a time when increasing numbers of young adults with ADHD are attending college (Pryor et al., 2010; Wolf, 2001), practice guidelines for clinically managing this condition on college campuses remain sparse. With limited access to appropriate diagnostic assessment and treatment services (DuPaul & Weyandt, 2009), college students with ADHD are at significantly elevated risk for adverse educational (e.g., not finishing school), vocational (e.g., unemployment), psychological (e.g., depression, substance abuse), and social (e.g., risky sexual behavior) outcomes for which there are substantial personal and societal costs. To help guide the development of evidence-based assessment and treatment practices that can be used on college campuses to reduce this risk, this study will examine the manner in which ADHD impacts the educational, vocational, psychological, and social functioning of college students over a four year period of time.